1. Field of the Invention
The present invention relates to a charge control system for a lithium battery, and more especially, to the charging system controlled by a microprocessor.
2. Background of the Related Art
Due to the popularity of the wireless communication and the technological trend, a hand-held apparatus with the features of lightness, handiness, convenience and multi-function is popular and widely used. In order to satisfy the practical and convenient requirements, the market of the batteries for the hand-held apparatus is increasing day by day. To satisfy the requirement of the user who needs the long standby time, the charging battery with large capacity is a very important essential accessory. Further, in order to fully employ the efficiency of the charging battery, using a charging-completed battery is beneficial for the economic consideration. However, if the user doesn't know whether the battery is charged completely or not and if the charging process doesn't stop automatically, it is easy to reduce the battery lifetime, damage the battery, and be dangerous. Therefore, how to automatically check the charging status and the existing voltage of the battery is one of urgent issues for the hand-held apparatus.
A conventional charging way of the hand-held apparatus is to add a charging chip into the hand-held apparatus to control the charging status and handle the requirement of the charging battery. However, due to the demand of the miniaturization of the hand-held apparatus and the increment of the electric component configured on the printed circuit board for raising the functions of the hand-held apparatus, the applicable layout and the space for the applying circuit of the hand-held apparatus are demanding day by day. Therefore, in a prerequisite of automatically checking the charging status and the existing voltage of the battery and not affecting the charging efficiency, the size reduction for the charging system is an urgent and important work.